聚合物改性沥青细观结构和重复蠕变特性研究

Research on Microstructure and Repeated Creep Properties of Polymer Modified Asphalt

针对内蒙古等西北部地区常用的3种聚合物改性沥青(SBS改性沥青、胶粉改性沥青和复合胶粉改性沥青),利用扫描电子显微镜(SEM)观察它们的细观结构形貌,得到改性剂在沥青中的分布状态及其与沥青间的界面结合特性,发现3种改性沥青的改性剂与沥青间均具有良好的界面融合性.利用动态剪切流变仪(DSR)对3种改性沥青进行不同温度和荷载应力下的重复蠕变试验,通过对累积应变、蠕变劲度的黏性部分GV随荷载和温度变化规律的分析表明:3种改性沥青随加载次数、温度及应力大小变化的规律相同,但同样条件下胶粉改性沥青具有最低的温度敏感性、最小的累积应变和最大的GV值,说明其具有最好的抗高温变形性能,其次为复合胶粉改性沥青.

Three polymer modified asphalts（SBS modified asphalt, crumb rubber modified asphalt and com-pound crumb rubber modified asphalt） widely used in Inner Mongolia and northwest region were analyzed. The scanning electron microscope was used to observe modifiers distribution in asphalt and microcosmic appearance of asphalt. It was shown that the interface between modifiers and asphalt had good compatibility. Then the repeated creep tests for three modified asphalts at different temperatures and stresses were carried out by dynamic shear rheology instrument. Cumulative strain and the viscous portion Gv of creep stiffness were analyzed. The results indicate that they have the same change law when loading number, temperature and stress magnitude change. Crumb rubber modified asphalt has the lowest sensitivity to temperature, the smallest cumulative strain and the largest Gv under the same condition, so it has the best high-temperature stability property, followed by compound crumb rubber modified asphalt.